Cannot access Samba share from Windows 8, but I can in Windows 7

Question

I´m trying to connect to my Samba share in my QNAP NAS from a Windows 8 client. The name and password are the same both in the Windows client and the NAS server. I got an authentication error, so I tried the same thing in Windows 7 and it works. So what is the difference between Windows 7 and Windows 8? What can I do to authenticate correctly without needing to use different credentials to access my Samba share?

Solution

Windows 8 and Windows 2012 introduced a "Secure Negotiate" feature to SMB, and they're configured to require Secure Server Signing by all SMB servers. The fix is to either tell the SMB server to enable signing (assuming your server is capable of signing), or to tell your Windows 8 client(s) to disable Secure Negotiate.

See Microsoft's description of this problem, or this page dealing with the same issue on a NetApp filer.

QNAP may have an upgraded firmware for your NAS which supports SMB 2.24 or newer, and the SMB signing necessary for native communication with newer Windows clients. They at least do for the Turbo NAS. So if you have a Turbo NAS, you could take this route.

Disabling Secure Negotiate on a Windows 8 client is easy, though. Start PowerShell, and enter the following command:

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters" RequireSecureNegotiate -Value 0 -Force

Note that this can also be easily changed later with -Value 1, if an upgrade to the NAS firmware comes later on.

Comments

[Abraham]

i also tried to change some security group policies without sucess. Samba on server is configured so it can be authenticated with NTLM2 and it can encript password.

[Ryan Ries]

Ok... one other idea. How about the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa key, change the value of LmCompatibilityLevel to whatever it is on your Windows 7 machine, and reboot again

[Abraham]

Hi. I found new qnap firmware in website (not in autoupdate). So new one is 4.0.5 that comes with samba 3.6.18. Now it is compatible with SMB 2. But i´m getting the same problem with authentication in windows 8. Any ideas? Thanks

[Jack]

I have the same issue, @AbrahamBorbujo. Trying to access a QNAP share with a Windows 8 computer asks for credentials. Accessing the same share with the same user on Windows 7 goes right in.

[Abraham]

I just made some test and discovered that Windows 8 can create two different types of user accounts. If you choose to create a new account without log into Microsoft account (local account) you can autenticate normally as windows 7 did. But if you chose the Microsoft account type, then you cannot acces samba shares as usual but manually writing credentials.